THE EFFECT OF REGRINDING BEARING SURFACES ON STRESSES IN OVERLAPPED CRANKSHAFTS

Regrinding the crankpin and/or the journal of a crankshaft changes the shape and most of the important dimensions. It reduces the overlap an d increases the stresses in the crankpin and journal fillets. Strain-g auged model tests and finite element calculations for simply supported , single-crank throws have been carried out for four shapes: the stand ard design, reduced crankpin only, reduced journal only and both beari ng surface diameters reduced by 5 per cent. Radial loading of the cran kpin, pure radial bending and pure torsion have been applied separatel y. The stresses have been normalized with respect to the nominal bendi ng stresses in the neck (the minimum section) between crankpin and jou rnal fillets. The resulting stress concentration factors are reduced b y regrinding.